The long-term goal is the complete elucidation of bioluminescence. This involves isolation, characterization and structural determination of key components, elucidation of the mechanisms of light-emitting reactions, and understanding the biochemical relationships among various bioluminescent systems. Our proposed research plan includes: (a) unequivocal elucidation of the pathway of luminescent reactions of the ostracod Cypridina and the firefly by the 0-18 tracer technique; (b) structural study of the active site of the photoprotein aequorin; (c) structure of the fluorescent substance "F" of the euphausid Meganyctiphanes; (d) structure of the chromophore of the green fluorescent protein "GFP" of the jellyfish Aequorea; (e) structure of the chromophore of the purple protein cofactor of the limpet Latia; (f) structure of the luciferin of the fireworm Odontosyllis, in collaboration with Dr. Kishi, Harvard University; (g) the bioluminescent systems of the sea cactus Cavernularia and the squid Watasenia.